|Election year|# of constituency votes|# of party list votes|% of party list votes|# of overall seats won|+/–|
|---|---|---|---|---|---|
|1949||6,934,975|29.2|131 / 402||
|1953|8,131,257|7,944,943|28.8|162 / 509|22|
|1957|11,975,400|11,875,339|39.7|181 / 519|19|
|1961|11,672,057|11,427,355|36.2|203 / 521|22|
|1965|12,998,474|12,813,186|39.3|217 / 518|14|
|1969|14,402,374|14,065,716|42.7|237 / 518|20|
|1972|18,228,239|17,175,169|45.8|242 / 518|5|
|1976|16,471,321|16,099,019|42.6|224 / 518|18|
|1980|16,808,861|16,260,677|42.9|218 / 497|6|
|1983|15,686,033|14,865,807|38.2|193 / 498|25|
|1987|14,787,953|14,025,763|37.0|186 / 497|7|
|1990|16,279,980|15,545,366|33.5|239 / 662|53|
|1994|17,966,813|17,140,354|36.4|252 / 672|13|
|1998|21,535,893|20,181,269|40.9|298 / 669|43|
|2002|20,059,967|18,484,560|38.5|251 / 603|47|
|2005|18,129,100|16,194,665|34.2|222 / 614|29|
|2009|12,077,437|9,988,843|23.0|146 / 620|76|
|2013|12,835,933|11,247,283|25.7|193 / 631|42|

Question: after 1949, how many consecutive years did the number of overall seats increase?
Answer: 6